隐伏岩溶条件下的上部结构-基础-地基共同作用数值模拟分析
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摘要
基于龙岗区某超高层大夏,建立岩溶地基-基础-上部结构共同作用的有限元计算模型,模拟分析溶洞的应力、应变、位移及桩基础受力性能,并将分析结果与传统设计方法(上部结构与地基基础分离成两部分计算)进行对比分析,指出岩溶地基条件下传统设计方法的局限性。其研究结果表明:对于岩溶地基而言,共同作用对柱产生的次应力较小,但个别角柱次应力较大;剪力墙的次应力较大,且其布置方式对共同作用有较大影响,此应力随楼层的增加衰减很快;针对岩溶地基,筏板基础是比较适合的基础形式,在共同作用中起很大作用。
The research object of this paper is a super high-rise building in Longgang district,Shenzhen,with a total building area of 127,262m~2.The main building is a frame-tube structure with 44 floors above ground and 3floors underground.The foundation is in the form of boring cast-in-situ pile,of which 44%of the piles have been installed in the area of karst caves.The stability of the karst caves and their influence on the overall structure should be considered in the construction process.The interaction of the superstructure,foundation ground and the pile foundation should be analyzed.In this paper,a conceptual model for the interaction of the three complements was hence established.Using finite element method to simulate the stress,strain,displacement and mechanical behavior of the pile foundation was conducted.The simulated results were analyzed and compared with those obtained by traditional design method which separated the upper structure and the pile foundation into two independent parts with no interaction in the numerical simulation.The comparative results shows that the stress difference of pile foundation increases with the increase of pile foundation stiffness;and the difference may reach 18.2%.Meanwhile along with the increase of the pile foundation stiffness,the overall stress of pile group increases by 13.7% and the average foundation ground settlement decreases by 4.9%,leaving little effect on the difference of foundation ground settlement.The simulated results also show that the interaction of the superstructure,foundation ground and pile foundation has a minor stress on the secondary stress acts on the building pillars.However,the secondary stresses of individual angular pillar and the shear wall are much large.The arrangement of the latter has a great influence on the interaction;and the stress decreases rapidly with the increase of the floor.Through this study,it is realized that in a karst area raft foundation is a suitable one,as plays an important role in adjusting the interaction of the three components.Based on the interaction method for analyzing the interaction of karst foundation ground,boring cast-in-situ pile foundation and the upper structure,the calculation results of pile foundation stress are uniform,the difference of ground settlement is small,and the stiffness of the superstructure can effectively solve the problem of uneven settlement of the foundation ground,which suggests that the stability of the karst foundation is good.
The research object of this paper is a super high-rise building in Longgang district,Shenzhen,with a total building area of 127,262m~2.The main building is a frame-tube structure with 44 floors above ground and 3floors underground.The foundation is in the form of boring cast-in-situ pile,of which 44%of the piles have been installed in the area of karst caves.The stability of the karst caves and their influence on the overall structure should be considered in the construction process.The interaction of the superstructure,foundation ground and the pile foundation should be analyzed.In this paper,a conceptual model for the interaction of the three complements was hence established.Using finite element method to simulate the stress,strain,displacement and mechanical behavior of the pile foundation was conducted.The simulated results were analyzed and compared with those obtained by traditional design method which separated the upper structure and the pile foundation into two independent parts with no interaction in the numerical simulation.The comparative results shows that the stress difference of pile foundation increases with the increase of pile foundation stiffness;and the difference may reach 18.2%.Meanwhile along with the increase of the pile foundation stiffness,the overall stress of pile group increases by 13.7% and the average foundation ground settlement decreases by 4.9%,leaving little effect on the difference of foundation ground settlement.The simulated results also show that the interaction of the superstructure,foundation ground and pile foundation has a minor stress on the secondary stress acts on the building pillars.However,the secondary stresses of individual angular pillar and the shear wall are much large.The arrangement of the latter has a great influence on the interaction;and the stress decreases rapidly with the increase of the floor.Through this study,it is realized that in a karst area raft foundation is a suitable one,as plays an important role in adjusting the interaction of the three components.Based on the interaction method for analyzing the interaction of karst foundation ground,boring cast-in-situ pile foundation and the upper structure,the calculation results of pile foundation stress are uniform,the difference of ground settlement is small,and the stiffness of the superstructure can effectively solve the problem of uneven settlement of the foundation ground,which suggests that the stability of the karst foundation is good.
引文
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[2]郭长宝,郭书泰,彭涛,等.辽宁省大窑湾某建筑场地岩溶发育特征及工程地质条件评价[J].中国岩溶,2010,29(2):176-182.
[3]WANG Jiying.Probe of Pile Foundation Design in Karst Area[J].Northern Communications,2007(12):47-48.(In Chinese)
[4]李肖南,阎长虹,许宝田,等.无锡某地基埋藏型岩溶发育特征及充填物来源[J].中国岩溶,2015,34(1):79-85.
[5]LI Qian-yin.Further study on formation mechanism of karst collaps[J].The Chinese Journal of Geological Hazard and Control,2009,20(3):52-55.(In Chinese)
[6]肖武权.娄新高速公路岩溶发育特征与地基处理方案优化研究[J].中国岩溶,2013,32(2):161-166.
[7]ZHAO Minghua,YUAN Tengfang,LI Li,et al.Computation Study on Safety Thickness of Bearing Rock Strata at Ends of Piles in Karst Area[J].Highway,2003(1):124-128.(In Chinese)
[8]CHENG Ye.Stability Evaluation Method and Application of Highway Roadbed and Bridge Foundation in Karst Region[D].Changsha:Hunan University,2005.(In Chinese)
[9]CAO Wen-gui,CHENG Ye,ZHAO Ming-hua.Studies on numerical manifold method for determination of safe thickness of karst roof in roadbed[J].Chinese Journal of Geotechnical Engineering,2005,27(6):621-625.(In Chinese)
[10]ZHAO Min-hua,CHENG Ye,CAO Wen-gui.Fuzzy method for the stability analysis of cave roof under pile tip in karst region[J].Chinese Journal of Rock Mechanics and Engineering,2005,24(8):1376-1383.(In Chinese)
[11]ZHAO Ming-hua,ZHANG Rui,HU Bo-xue.Analysis of stability of cave roof under pile tip in karst area[J].Journal of Highway and Transportation Research and Development,2009,26(6):13-16,31.(In Chinese)
[12]董建国,赵锡宏.高层建筑地基基础[M].上海:同济大学出版社,1996.
[13]宰金珉,宰金璋.高层建筑基础分析与设计[M].北京:中国建筑工业出版社,1994.
[14]阴可,张永兴,丁志诚.高层建筑岩石洞室地基稳定性分析[J].重庆建筑大学学报,2001,23(1):18-20.
[15]陈希昌.高层建筑物上部结构与基础及地基共同作用问题研究[D].重庆:重庆建筑大学,1997.
[16]袁聚云,赵锡宏,董建国.高层空间剪力墙结构与地基(弹塑性模型)共同作用的研究[J].建筑结构学报,1994,15(2):60-69.
[17]韦树英,韦斌.钢筋混凝土结构的弹塑性分析[M].桂林:广西师范大学出版社,2001.
[18]陈惠发.土木工程材料的本构方程(第一卷,第二卷)[M].武汉:华中科技大学出版社,2001.
[19]费康,张建伟编著.ABAQUS在岩土工程中的应用[M].北京:中国水利水电出版社,2013.
[20]连镇营,韩国城,孔宪京.强度折减有限元法研究开挖边坡的稳定性[J].岩土工程学报,2001,23(4):407-411.
[21]Ugai K.A Method of Calculation of Total Factor of Safe of Slops by Elasto-Palstic Fem[J].Soils and Foundations,1989,29(2):190-195.
[22]郑宏,李春光,李焯芬,等.求解安全系数的有限元法[J].岩土工程学报,2002,24(5):626-628.
[23]张林,杨志刚,钱庆强,等.溶洞顶板稳定性影响因素正交有限元法分析[J].中国岩溶,2005,24(2):156-159.
[24]周维垣,杨若琼,剡公瑞.高拱坝稳定性评价的方法和准则[J].水电站设计,1997,13(2):2-8.
[25]滑帅.广东岩溶区某输电塔桩基稳定性数值模拟分析[J].中国岩溶,2014,33(1):44-50.
[2]郭长宝,郭书泰,彭涛,等.辽宁省大窑湾某建筑场地岩溶发育特征及工程地质条件评价[J].中国岩溶,2010,29(2):176-182.
[3]WANG Jiying.Probe of Pile Foundation Design in Karst Area[J].Northern Communications,2007(12):47-48.(In Chinese)
[4]李肖南,阎长虹,许宝田,等.无锡某地基埋藏型岩溶发育特征及充填物来源[J].中国岩溶,2015,34(1):79-85.
[5]LI Qian-yin.Further study on formation mechanism of karst collaps[J].The Chinese Journal of Geological Hazard and Control,2009,20(3):52-55.(In Chinese)
[6]肖武权.娄新高速公路岩溶发育特征与地基处理方案优化研究[J].中国岩溶,2013,32(2):161-166.
[7]ZHAO Minghua,YUAN Tengfang,LI Li,et al.Computation Study on Safety Thickness of Bearing Rock Strata at Ends of Piles in Karst Area[J].Highway,2003(1):124-128.(In Chinese)
[8]CHENG Ye.Stability Evaluation Method and Application of Highway Roadbed and Bridge Foundation in Karst Region[D].Changsha:Hunan University,2005.(In Chinese)
[9]CAO Wen-gui,CHENG Ye,ZHAO Ming-hua.Studies on numerical manifold method for determination of safe thickness of karst roof in roadbed[J].Chinese Journal of Geotechnical Engineering,2005,27(6):621-625.(In Chinese)
[10]ZHAO Min-hua,CHENG Ye,CAO Wen-gui.Fuzzy method for the stability analysis of cave roof under pile tip in karst region[J].Chinese Journal of Rock Mechanics and Engineering,2005,24(8):1376-1383.(In Chinese)
[11]ZHAO Ming-hua,ZHANG Rui,HU Bo-xue.Analysis of stability of cave roof under pile tip in karst area[J].Journal of Highway and Transportation Research and Development,2009,26(6):13-16,31.(In Chinese)
[12]董建国,赵锡宏.高层建筑地基基础[M].上海:同济大学出版社,1996.
[13]宰金珉,宰金璋.高层建筑基础分析与设计[M].北京:中国建筑工业出版社,1994.
[14]阴可,张永兴,丁志诚.高层建筑岩石洞室地基稳定性分析[J].重庆建筑大学学报,2001,23(1):18-20.
[15]陈希昌.高层建筑物上部结构与基础及地基共同作用问题研究[D].重庆:重庆建筑大学,1997.
[16]袁聚云,赵锡宏,董建国.高层空间剪力墙结构与地基(弹塑性模型)共同作用的研究[J].建筑结构学报,1994,15(2):60-69.
[17]韦树英,韦斌.钢筋混凝土结构的弹塑性分析[M].桂林:广西师范大学出版社,2001.
[18]陈惠发.土木工程材料的本构方程(第一卷,第二卷)[M].武汉:华中科技大学出版社,2001.
[19]费康,张建伟编著.ABAQUS在岩土工程中的应用[M].北京:中国水利水电出版社,2013.
[20]连镇营,韩国城,孔宪京.强度折减有限元法研究开挖边坡的稳定性[J].岩土工程学报,2001,23(4):407-411.
[21]Ugai K.A Method of Calculation of Total Factor of Safe of Slops by Elasto-Palstic Fem[J].Soils and Foundations,1989,29(2):190-195.
[22]郑宏,李春光,李焯芬,等.求解安全系数的有限元法[J].岩土工程学报,2002,24(5):626-628.
[23]张林,杨志刚,钱庆强,等.溶洞顶板稳定性影响因素正交有限元法分析[J].中国岩溶,2005,24(2):156-159.
[24]周维垣,杨若琼,剡公瑞.高拱坝稳定性评价的方法和准则[J].水电站设计,1997,13(2):2-8.
[25]滑帅.广东岩溶区某输电塔桩基稳定性数值模拟分析[J].中国岩溶,2014,33(1):44-50.